Over eight days of testing, 369 drone flights launched and landed at a rural test site outside Blacksburg. In a slice of airspace that covered less than a quarter of a mile, as many as 12 aircraft were sometimes flying at once. These flights were dense by design, choreographed to answer a question that's increasingly crucial to drone integration: How can drones share the air without bumping shoulders?
source https://techxplore.com/news/2020-11-bracing-busier-drone-traffic.html